The problem of psychosis is not often considered independently from the conditions with which it is associated. Investigations in this laboratory have documented neuromagnetic abnormalities using auditory probe tasks in bipolar patients with a history of psychosis vs. those without such history. This suggests the possibility to differentiate brain variables related to psychosis from those related to the mental illness per se. The investigators now propose to study 30 subjects with bipolar disorder and a history of psychosis, 30 bipolar subjects with no history of psychosis, and 30 controls (15 males in each group). Magnetic source imaging of auditory (M100 generated in Heschl's gyrus or continuous planum temporale) and somatosensory (M50 generated in 3b of postcentral gyrus). MRI data from these subjects will examine, identify and quantify the source of these MEG signals to assess possible cortical reorganization as an index of psychosis. The hypothesis is that subjects with a history of psychosis will demonstrate specific abnormalities on functional and structural measures. Altered tototopy and somatotopy will be examined as antecedents or results of psychosis. The findings will help identify individuals at risk for illness, and separate disease and psychosis-associated brain changes in mental disorders.